Dd-mount-tar

From wikipost
Revision as of 01:00, 23 December 2013 by Admin (talk | contribs)
(diff) ← Older revision | Latest revision (diff) | Newer revision → (diff)
Jump to navigation Jump to search
The printable version is no longer supported and may have rendering errors. Please update your browser bookmarks and please use the default browser print function instead.
  • Extract from a .tar.gzipped dd file straight to another device
 When creating a dd image of a whole disk it can be worthwhile compressing it using .tar.gz
 The resulting file can still be extracted and dd'ed to a new disk all in one go:
 # tar xz0f disk-image_dd.tar.gz | dd of=/dev/sda bs=1M


  • To watch the progress of an ongoing dd command, send it the -USR1 kill signal:
 - find the pid of the dd command
 - send the kill command: 
      # kill -USR1 <pid>
  This will not kill the running dd process, it's just a method of communicating signals to the dd program.


  • mount a partition inside a whole-disk dd image
 - install parted if you haven't done so already
 - run parted on the dd file
 - switch to bytes  'unit B'
 - print the partition table 'print'
 - take note of the Start value of the partition you wish to mount (drop the 'B' at the end of the number!)
 - quit parted 'quit'
 - mount the partition using the offset argument
    
      # mount whole-disk.dd -o loop,offset=<startposition> /mnt/partition


  • mount a partition inside a tar.gzipped whole-disk dd image
 - use the above technique to obtain the offset for the partition you wish to mount
 - install kpartx if you haven't done so already
 (http://unix.stackexchange.com/questions/31669/is-it-possible-to-mount-a-gzip-compressed-dd-image-on-the-fly)